I am no cat expert, but I do not think it is normal for a cat sitting in the litter all day long.

Has he been pooping normally?
Sorry I had to ask lol. Think about it, when someone is sitting in that position for a long time, the first thing comes to mind is that he must be having trouble to ... well you know.

Aw, this is really sad for me to hear. I have never heard of such a thing so therefore I would assume that it is not normal.
I would check this problem out because this is one of those matters that I would try not to let go out of my hands. Do not neglect this issue
and everything will be fine. I wish you the best of luck and hope your cat will be in great health very soon! Sending you the best thoughts and wishes!

I worked at an animal shelter over the summer, and finding cats sitting in or sleeping in their little boxes was actually quite common, believe it or not. Cats sometimes see their litter box as a "safe spot", which is why most of the cats in the shelter did it (at least, that's what the vet tech told me when I asked her about it). Maybe something stressed your kitty out? It can also mean they just aren't feeling well, which would make sense with the IBD. If he's eating, drinking, pooping, and peeing normally, things are probably okay. If not, time for a checkup with the vet! Sometimes males spend extra time in the box if they have a blockage in the urinary tract, but you'll usually see them squatting, straining, or scratching around if that's the case.

I am very very glad to know it is quite common. I am glad you can put forward a vets opinion jen, it really does make me feel better. It makes me feel a little bit worried that he even needed a safe spot in the first place, but I never know what is going on in his head! He hasn't showed any other signs that his IBD is flaring up again, and hasn't been stressed as far as I can tell. He has been behaving like his old self, lots of cuddles and attention, and still lots of energy to play. He eats and drinks fine, I haven't checked on his poop, but he hasn't thrown up or gagged, or had loose poop stuck around his rear end. (which is usually a sign of band things to come). I will keep an extra eye on him over the next few days, I have been mixing extra filtered water into his food to try and keep him hydrated too.